As a method for forming an image according to the thermal transfer, a sublimation type thermal transfer recording method is known, wherein a thermal transfer sheet in which sublimation type dyes as recording materials are supported on a substrate made of a plastic film or the like, and a thermal transfer image-receiving sheet in which a receiving layer is provided on another substrate made of a paper the like are superposed on each other in order to form a full color image. Since this method uses the sublimation type dyes as color materials, this method excels in reproducibility and gradation of halftone, and thus, a full-color image can be clearly expressed as the original image on the image-receiving sheet.
When a sublimation type thermal transfer printer for forming an image according to the sublimation thermal transfer method is used in order to form a full-color image on the thermal transfer image-receiving sheet, it is necessary to perform a plurality of times of printing on one screen, for example, three times of printing for Y (yellow), M (magenta), C (cyan) inks, or four times of printing for these inks and an additional protective layer (OP). In such a case, if the conveyance of the thermal transfer image-receiving sheet in the sublimation type thermal transfer printer becomes poor, deviations occur in the feed rate of the thermal transfer image-receiving sheet and in the attaching positions of the inks, and thereby, the turbulence is caused in the image. Therefore, good transportability at the time of image formation is required of the thermal transfer image-receiving sheet.
Under these circumstances, for example, in Patent Literature 1, a thermal transfer image-receiving sheet has been disclosed, which is provided with a rear face layer comprising a styrene-butadiene rubber having a glass transition temperature of 50-90° C., a polyethylene wax, and an anionic polystyrene resin.
Also recently, with respect to the thermal transfer image-receiving sheet for sublimation type thermal transfer printer applications, a high texture has been required in addition to the improvement of the transportability during the image formation. Specifically, not only for the image receiving face that is an image forming face of the thermal transfer image-receiving sheet, but also for the rear face side the high texture is required. Incidentally, in the thermal transfer image-receiving sheet, as a supporting member for supporting the receiving layer and the rear face side layer, a paper or plastic film or the like is generally used. However, since these supporting members tend to involve any contaminants or defects, in the case that the conventionally known rear face side substrate is simply provided on the surface of the supporting member that is opposite to the other surface on which the receiving layer is provided, it is impossible to cover up the contaminants or defects in the supporting member, and therefore, the thermal transfer sheet is obliged to be low in the texture of the rear face side thereof. As described in the Patent Literature 1, although a white opaque film or the like, which is prepared by adding white pigment or the like to the film material and then forming the film, is known as the supporting member of the thermal transfer image-receiving sheet, it is impossible to cover up the contaminants or defects in the supporting member completely by using such a white opaque film or the like. Thus, there is room for improvement in the concealment of the contaminants or defects. In addition, with respect to the rear face side of the thermal transfer image-receiving sheet, it is also required further improvement in the texture.